Abstract

Graphene-based composite material was prepared and its electrochemical supercapacitive properties were investigated. The composite material comprises of mixed manganese oxide (Mn2O3) and cobalt oxide (Co3O4) crystal distributed on the reduced graphene oxide (RGO) matrix. Structure and morphology of the composite was studied by X-ray diffractometry, high resolution transmission electron microscopy and scanning electron microscopy. The surface functional groups and chemical composition were confirmed by Fourier transform infrared spectroscopy, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. Thermal stability was investigated by thermo gravimetric analysis. Electrochemical supercapacitive performance of the composite was investigated by cyclic voltammetry (CV) and chronopotentiometry. CV and chronopotentiometry results suggested that electrochemical performance of the composite material is better than RGO and mixed Mn2O3 and Co3O4. Specific capacitance of composite was obtained 210 F g−1 at scan rate of 5 mV s−1 and 184 F g−1 at current density of 2 A g−1, respectively. Moreover, the composite showed high cyclic stability with the retention of about 87% capacitance after 1000 charge/discharge cycles. These results suggest the importance and potential of graphene based composite in supercapacitor application.